When to use FL size and small base size dies?

[Rainy Winchester]

I'm slightly confused as to when a FL size die or small base size die is needed. I shoot a semi auto mini 14, AR-15, and 338 win mag, then a bolt 25-06, 30-06 and 300 win mag, and pump 30-06. So can I FL size all of them or do some work better with small base dies? Which rifle needs what die?

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[decay]

Normally auto-loaders need either full length resized or in some cases small base dies . If you read the reloading manual they cover this pretty well like in the Speer #14 or the Sierra manual .

 

[Rainy Winchester]

I have the lyman 49th ed., just don't remember it saying anything about the difference. I need to get off my butt and order some more manuals, like the speer and hornady ones.

 

[Greenbug]

Use the small base dies on brass used in your autoloaders and your pump rifle. The full length dies will work fine on brass used in your bolt action guns. Bolt action guns have more power when it comes to seating a round in the chamber, so the brass used in these rifles does not need to be sized as tightly as the brass used in your pump and autoloading rifles wich have less power when seating a round in the chamber.

 

[Rainy Winchester]

So I have a FL die for 223 but haven't reloaded anything for 223 yet. How will that die affect the brass, accuracy, anything else fired from
the semi auto guns?

 

[Rainy Winchester]

Use the small base dies on brass used in your autoloaders and your pump rifle. The full length dies will work fine on brass used in your bolt action guns. Bolt action guns have more power when it comes to seating a round in the chamber, so the brass used in these rifles does not need to be sized as tightly as the brass used in your pump and autoloading rifles wich have less power when seating a round in the chamber.

Ok, that makes sense. Thank you.

 

[Blitzkrieg]

You MUST use a SB die for 5.56/autoloaders. Greenbug pretty much nailed it. A case gauge is very handy as well

 

[Rainy Winchester]

You MUST use a SB die for 5.56/autoloaders. Greenbug pretty much nailed it. A case gauge is very handy as well

Oh its a must? Chit, looks like I better trade or sell my FL 223 dies for a SB die. Thank you guys for clearing that up.

 

[DieselScout]

Oh its a must? Chit, looks like I better trade or sell my FL 223 dies for a SB die. Thank you guys for clearing that up.

Do some other research before you do. Plenty of people out there reloading for semi-auto's without small base dies.

 

[bockja]

It really depends on how tight of chamber your particular gun has. Most AR's will be just fine with a FL die. However if your particular gun is on the small side of chamber tolerances, then it may require small base dies. You can use a small base die just to be safe but to the detriment of brass life. This may be a necessity for your gun, but probably not. Regarding the bolt guns, either FL size, or neck size (only if using in one firearm). If you neck size, you may need to FL size every 4 to 5 firings to bump the shoulder back into spec. A survey of people reloading for the AR showed that about 76% FL resize, 12.5% SB resize just because, and 11.5% SB resize because they need to.

Reloading for AR15: Standard or Small base die? - THR

 

[Certaindeaf]

It's a rare thing to "have" to use SB dies. It's perhaps most/more common for/with "springy" and powerful guns like some Savage levers.

 

[kfbigdog]

I am new to loading but my loading buddy has been loading for 30+ years. He has preached to me that you only need to use the FL (full length) dies when there is a question of whether or not your brass was shot from your gun. 1 shoot 2-3000 rounds of 223 per year in Sregon at squeekers. I only FL size brass the first time I receive brass from friends or buy used brass. I shoot a Rem 700 Varmit special only. I only neck size any brass that is reloaded after it is shot from my gun. FL sizing causes excessive wear the the casing walls. I can use brass 7-10 times before I have to recycle it. I'm only telling you what works best for me. Hope this helps.
bigdog

 

[Blitzkrieg]

Do some other research before you do. Plenty of people out there reloading for semi-auto's without small base dies.

None of my 5.56 weapons will chamber a 5.56 case unless I run them through a SB die. Mini 14s/AR15s

 

[DieselScout]

None of my 5.56 weapons will chamber a 5.56 case unless I run them through a SB die. Mini 14s/AR15s

I understand that is your experience, but from the hours of reading and research I did when it came to buy my dies, I would say your the exception rather then the rule. Regardless if the OP has FL dies, then he should give them a try. If they don't work, trade them out for SB or just buy a SB sizing die.

 

[Blitzkrieg]

That makes sense.. but I can tell you that I had to use every last tidbit of sizing ability on those SB dies, too

I also figure it's a good idea to load up ammo that will work well in any 5.56 (unless it has a tight match spec or something)

 

[Rainy Winchester]

Well I will try the FL dies for both the mini 14 and AR, maybe load a mags worth for both and see how they work. If I need a SB die then I guess it couldn't hurt to have one. So does the same go for the autoloader 338 wm and 30-06 pump? The 338 in a BAR ad I thought I ran across something for using SB dies in a BAR. But I could be wrong, there's a first time for everything

 

[bellarum]

I FL size for 2 ARs and have had zero issues. (1,000s of rounds) I only load them 6-7 times. Brass used is random year LC and FC.

 

[sterzenbach]

So I have a FL die for 223 but haven't reloaded anything for 223 yet. How will that die affect the brass, accuracy, anything else fired from
the semi auto guns?

My mini14 loaded FL 223 with no issues. Just make sure you set those bullets slightly deeper to clear the mag. I had issues with full length in my M1A, it would jam on loading. Re sized with a new small base die and solved the issue.

 

[ron]

I have used RCBS FL dies on many different match grade ARs with no issues.
I have reloaded many thousand of 223s over the last 15 years. Problems in sizing 223 cases can sometimes be
attributed to not adjusting the sizer die in far enough to bring down the shoulder of the case to specs. The RCBS
precision Mic can be used to measure fired cases. I size my cases to what new ammo measures since they are
fired in different semi autos. With a bolt gun you can measure fired cases and adjust the sizer die to do minimum
sizing of the case.
RCBS Precision Mic 223 Remington

 

[Rainy Winchester]

My mini14 loaded FL 223 with no issues. Just make sure you set those bullets slightly deeper to clear the mag. I had issues with full length in my M1A, it would jam on loading. Re sized with a new small base die and solved the issue.

Ok, I'll keep that in mind. And if I have any trouble loading or ejecting I'll purchase a sb die.

I have used RCBS FL dies on many different match grade ARs with no issues.
I have reloaded many thousand of 223s over the last 15 years. Problems in sizing 223 cases can sometimes be
attributed to not adjusting the sizer die in far enough to bring down the shoulder of the case to specs. The RCBS
precision Mic can be used to measure fired cases. I size my cases to what new ammo measures since they are
fired in different semi autos. With a bolt gun you can measure fired cases and adjust the sizer die to do minimum
sizing of the case.
RCBS Precision Mic 223 Remington

Yea adjusting the die far enough down is something I try to do my best at. The precision mic dies are nice, but I cant justify paying that much for a die set.